Printing luminous dials



Jan. 24, 1928. 1,657,237

H. F. TALBOT PRINTING LUMINOUS DIALS Filed Nov. 18, 1926 INVENTOR Harrie YIN/10f ATTORNEY Patented Jan. 24, 1928.

UNITED STATES HABBIE F. TALBOT, OF THOMASTON,

COMPANY, OF LA SALLE, ILLINOIS,

CONNECTICUT, ,A S SIGNOB TO .WESTERN CLOCK A CORPORATION OF ILLINOIS.

rnm'rme LUMINOUS mans.

Application filed November 18, 1926. Serial No. 149,15

This invention relates to luminous dials, and more particularly to an apparatus and process for simultaneously printing a .plurality of letters of radium luminous material upon metal or enamel dials or other surfaces.

One object of this invention is to provide an apparatus of the above nature having a flexible transfer rinting pad which is adapted to receive gures of radium luminous paint from a die, and thereafter to print said figures upon a dial or other surface.

A further object is to provide a device of this nature which will be simple in construction, inexpensive to manufacture, easy to install and manipulate, compact, ornamental in appearance, and very efficient and durable in use.

With these and other objects in view there has been illustrated on the accompanying drawing one form in which the invention may be conveniently embodied in practice.

Figure 1 represents a front view in elevation ofthe dial printing apparatus.

Fig. 2 is a cross-sectional view of the transfer pad and its holder, shown in position above the die.v

Fig. 3 is a plan view of a die having luminous figures for a single clock face. so Fig. 4 is a plan view of a die having luminous figures or characters to be simultaneously printed upon a plurality of dial faces.

In the manufacture of luminous dials it has been customary in the past to paint the luminous figures or characters with a brush by hand labor. This operation was found to be hazardous to the operators due to the injurious ingredients, such as phosphorus 40 or radium contained in the luminous paint.

Attempts have been made to avoid this danger by devising machines which would mechanically print the radium luminous letters on dials and other similar surfaces, but

these machines hitherto have proven unsuccessful owing to the fact that the radium paint employed would not adhere properly to the surface being printed. Moreover, the non-luminous materials of the paint composition destroyed to some extent the luminous qualities thereof. An0ther-cause for the failure of these attempts was that the paints employed, owing to the large percentage of lacquer contained therein, dried too quickly to enable them to be used for a mechanica transfer process. By means of the present above and other disadvantages have been avoided. This has been accomplished by providing an improved composition of radrum luminous paint which will possess its full luminous qualities, and will not dry too quickly. The invention also involves an improved process for applying said paint, and an approved apparatus for mechanically prlnting the figures -of said paint upon a dial. One example of improved luminous paint embodying the present invention may be prepared as follows: I

Ten parts of varnish, such as copal, are mixed thoroughly with ten parts of Venice turpentine, and three parts of balsam of Copaiva. To the above mixture, radium luminous material, such as that known in the tradeas Undark Grade-13 and obntainin substantial percentages of radium chlori e or other radium salt and zinc sulphide is added. The whole mass is then invention, the i kneaded until it attains the consistency of soft putty. Ordinarily this consistency of the mass will be attained when an amount of radium luminous material has been added e 'ual to about two-thirds of the entire bulk. T e putty-like mass will then be thinned down, preferably with three parts of lavender oil, although th e oil maybe substituted in its place if esired 7 The metal or enamel dial is first prepared for the printing process by coating it with 7 black lacquer of standard composition, consisting for exampleof a solution of gun cotton in amylacetate, which is then allowed to dry. thoroughly. The next step is to apply to the black lacquer surface under the positions of the figures of the dial, a foundation coat of metallic oxide paint, preferably a paint known as flake-white, although an aluminum bronze paint may also be used. This foundation coat is allowed to stand until it becomes tacky, which generally requires about three-quarters of an hour. The figures of radium luminous paint of the above described composition are then applied to the dial by means of a printing pad constructed as hereinafter specified. The coat of luminous paint is then allowed to dry until it becomes-tacky. If desired, a second coat of radium paint may be printed adhering to dial 19, thereby over the first to increase the luminous effect thereof. If it is desired to still further enhance the luminosity, a light coat of dry luminous material may be dusted over the figures, as by a fine brush, the material not I the radium paint being brushed off. Finally, the entire dial iscovered with a light coat of transparent lac uer.

In carrying out this process it is very important that the foundation surface of metallic oxide paint be allowed to dry until tacky, as otherwise the figures of radium paint will not properly adhere thereto, In other words, the balance of adhesion between the. die, the pad, and the dial must be exactly correct. This balance is accomplished by timing the steps of the process carefullyaccording to the temperature and particular paint mixtures being used.

In applying the radium luminous paint to the figures of the dial, the paint mixture, prepared as described above, is first rubbed into the depressions of the die, as with a putty knife, and the surface scraped off clean. The printing pad is then caused to descend upon the die after the proper time interval, and by adhesion, gathers the material out of the die depressions. The pad 20 is then raised and the bed plate 13 of the apparatus is'moved to the left, as viewed in Fig. 1, to bring the dial or other surface to be printed directly underneath and in alinement with the pad 20. The pad is then forced downwardly into contact with the printing the figures thereon.

he apparatus employed for carrying out the above process will now be described. This apparatus comprises a base 10 substantially rectangular in form, said base having legs 11 at its four corners for supporting it upon a table or other surface.

The base 10 is provided with downwardly extending flanges 12 on its sides and ends, the end flanges being provided with slots to receive and guide a sliding bed plate 13. The bed plate 13 has down-turned ends 14 which are adapted to carry stop screws 15 which engage stops 16 on the end flanges 12 of the base.

The bed plate 13 is provided on its upperface with a pair of holders l6 and 17 for a die 18 and dial 19 respectively. When the bed plate 13 is in the extreme right-hand position shown in Fig. 1, the die-holder 16 will be directly under and in alinement with a transfer pad 20.

When, however, the bed plate 13 is in its extreme left-hand position, the dial-holder 17 will be in alinement with the sad 20 so that when the latter next de-' scen s, the luminous paint figures on the pad will be transferred or printed on the dial 19..

In the form of die 18 shown in Fig. 3, a plurality of depressed figures 21 are provided representing a single clock face, the

.to the die, as described above. of die 18 shown in Fig. 4, a plurality of depressions in said figures beingadapted to receive the radium luminous paint applied In the form smaller depressed figures are provided representing six watch faces 22. In the use of either form of die, however, it will be understood that a plurality of figures will be painted with each stroke of the pad 20.

The tranfer pad 20 is preferably constructed from ordinary printers roll made from gelatin composition, but said pad may be composed of rubber or any other suitable material if desired. The bottom surface 22 of the pad is preferably made spherical while the upper. part 22 of the pad is cylindrical. In order to prevent the pad 20 from spreading or bulging when pressure is applied thereto during the printing operation, a ring member 23 is tightly fitted around the cylindrical portion 22 of the pad just above the spherical portion 22* thereof.

The pad 20 is carried by a Hat cup-shaped holder 24, said holder being provided with a depending annular flange 25 and an upwardly extending neck 26. The neck 26 is made hollow and the interior surface thereof is threaded at 27 to receive a similarly threaded spindle 28 depending from the lower end of a rectangular plunger 29.

The plunger 29 is adapted to be guided by a pair of jaws 30 and 31, said jaws being secured at their rear ends to a curved post 32 mounted upon the base 10 of the apparatus.

The plunger 29 is normally held in raised position by tached at its lower end to an eye member 34 on the top of the plunger, said spring being secured at its upper end to a spring holding arm 35, the lower end of which is attached to the jaw 30 previously mentioned.

In order to enable the plunger 29 to be manually moved up and down whenever desired, provision is made of alever member 36 having a handle 37, said lever being pivoted on a pin 38 carried by the central part of the plunger 29. The opposite end of the lever 36 from the" handle 37 is connected at 39 to a downwardly extending link 40, said link being pivoted at its lower end upon a pin 41 rigidly mounted in a lug 42 projecting laterally from the jaw member 31.

In operation, when it is desired to print a plurality of figures with either of the dies shown in Figs. 3 and 4, the proper diet 18 or 18 is first placed in the die-holder 161 The of a putty knife. The'surface will then be scraped ofi" carefully. The dial 19 u n which the figures are .to

placed in the holder 17 and the die 18 is means of a spiral spring 33 at-.

be printed is t en.

placed in the holder 16, and said holders are fastened in the bed plate 13. The die is then rubbed over with the metal oxide paint, whereupon the operator will grasp the handle 37 and push the plunger 29 to move it down from the position shown in Figs. 1 and 2 until the pad 20 comes into complete contact with the die 18. This operation causes the pad 20 to flatten so that when the plunger 29 is raised,.the pad 20 will remove by adhesion the paint from the die depressions.

The bed plate 13' will then be slid to its other extreme position in the base 10, at which time the dial 19 will be in exact vertical alinement with the pad 20. The operator will then force the pad down again, printing the foundation coat upon the dial. This foundation coat is then allowed to dry until it becomes sufficiently tacky general] y about threequarlers of an hour. The same operation is then repeated for printing the coat of radium paint upon the dial fig-- ures. If it is desired to put on a second coat of radium paint, the first coat will be allowed.

to stand until it becomes sufficiently tacky. (about three-quarters of an hour) to cause the second coat to strongly adhere thereto. In any case a light final coat oftransparent lacquer will be applied to the entire surface of the dial.

One advantage of the present invention is that by the simultaneous printing of a plurality of figures, it is possible to speed up the application of radium luminous paint to dials to a very great extent.

A further advantage is that waste of the expensive luminous material is reduced and the quantity of such material applied to the figures on the dial will be absolutely uniform.

A further advantage of this invention is that it permits dials to be printed rapidly and accurately with less skilled labor.

While there has been disclosed in this specification one form in which the invention may be embodied, it is to be understood that this form is shown for the purpose of illustration only, and that the invention is not to be limited to the specific disclosure but'may cations and embodiments coming within the scope of the following claims.

Having thus fully described the invention what is claimed as new, and for which it is desired to secure Letters Patent, is:

1. The process of printing figures of radium luminous paint upon a dial or other surface, comprising applying a base coat of lacquer to said dial, applying a foundation coat of metallic oxide paint for said figures, allowing said paint to dry until tacky, applying to the figures a coat of radium luminous paint, allowing said radium luminous paint to dry until tacky, applying a second coat of radium luminous paint to said figures, and applying a finishing coat of lacquer to the entire surface of the dial.

2. The process of printing figures of radium luminous paint upon a dial or other surface, comprising applying a base coat to said dial, applying a foundation coat of paint for said figures, tacky, applying to the figures a coat of radium luminous luminous paint to dry until tacky, applying a-second coat of radium luminous paint to said figures, and applying a finishing coat to the entire surface of the dial.

3. The process of printing luminous figures upon a dial, comprising applying a foundation coat ofmetallic oxide paint to said dial, allowing said foundation coat to dry until tacky, applying a coat of radium luminous paint to said foundation coat, and applying a finishing coat upon said radium luminous paint.

4. The process of printing luminous figures upon a dial, comprising mechanically applying a coat of radium luminous paint simultaneously to a plurality of figures upon said dial, and applying a finishing coat to protect said radium luminous paint. L

In testimony whereof, I have aflixed my signature to this specification.

HARRIE F. TALBOT.

allowing said paint to dry until paint, allowing said radium 

